Abstract: A respirator comprising an outer mask in which is defined a main volume and an oronasal mask located within the outer mask and defining a secondary volume. Air for breathing enters the mask via a one-way valve and filter. Exhaled air exits the mask via an exhale conduit fitted with an exhale valve. A conduit is provided for the passage of air from the outer mask to the oronasal mask. The conduit is fitted with a one-way valve and a filter. The filter is such as to filter either particular or vapor challenges, or a mixture of these, as required.

Abstract: A respirator includes an outer mask defining a first volume. An oronasal mask defines a second volume. The oronasal mask is positioned within the first volume. A primary filter is affixed to the outer mask and a secondary filter is positioned within the first volume such that the secondary filter filters air traveling from the first volume to the second volume. The secondary filter filters air traveling around a portion of the second volume. The filters are arranged to filter either particles or vapors, or a mixture of these, as required.

Abstract: Self-calibrating apparatus and methods for dilution of an analyte-containing fluid, and in particular for dilution of analyte concentrations beyond the normal measurement range of a detector, without the requirement for other detectors. The apparatus is preferably a respirator test system for determining respirator mask fit in the presence of high aerosol challenge concentrations.

Abstract: A valve assembly (20) for a respirator comprises a valve body (25) having a valve outlet portion and a valve inlet portion which together define a valve cavity (30) for a valve mechanism (24) permitting gas flow from the valve inlet portion to the valve portion member, an air purge means comprising a purge inlet, connectable to an air pressure supply means, an air purge outlet (27) and an air deflection means (28) in which the deflection means is spatially arranged relative to the valve mechanism and purge outlet so that, in use, air exiting the purge outlet and incident the air deflection means provides a curtain of air over the valve mechanism.

Abstract: Self-calibrating apparatus and methods for dilution of an analyte-containing fluid, and in particular for dilution of analyte concentrations beyond the normal measurement range of a detector, without the requirement for other detectors. The apparatus is preferably a respirator test system for determining respirator mask fit in the presence of high aerosol challenge concentrations.

Abstract: Apparel suitable for providing protection against noxious agents, wherein the apparel comprises a laminate material that provides a substantially effective barrier against the noxious agents. It is preferred that the laminate material comprises two or more layers, at least one of which is a barrier layer that is a substantially effective barrier against the noxious agents and at least one of which is a protective layer that protects the at least one barrier layer.

Abstract: Apparel suitable for providing protection against noxious agents, wherein the apparel comprises a laminate material that provides a substantially effective barrier against the noxious agents. It is preferred that the laminate material comprises two or more layers, at least one of which is a barrier layer that is a substantially effective barrier against the noxious agents and at least one of which is a protective layer that protects the at least one barrier layer.

Abstract: A respirator system (10; 100) for a worker in an environment with hazardous airborne contaminants comprises a respirator (12, 112), a helmet (14, 114), a camera (40, 140), and a gas sample analyser (16, 116) capable of analysing samples of gas from within the respirator and in the immediate area near the user. An RF emitter (20, 120) sends a signal to a remote receiver (24, 124). The emitted signal is a real time view through the camera (40, 140) and overlaid on that is a graphical representation of the protection factor being achieved by the respirator. The system (100) may also have a data storage device (162, 170) to store data such as how protection factor varies with time and may have a position sensor (160). The provision of the position sensor (160) allows a map of contamination levels with position to be built up as a user moves around a site.

Abstract: A respirator (1) comprises an inner, oronasal, mask (2) enclosed within an outer, face sealing, mask (3) so as to define a cavity (4) therewith, a screw-threaded air inlet (5) for conducting inhaling air to the interior of the inner mask (2), a filter canister (7) for filtering the inhaling air, and an air outlet (8) for conducting exhaled air from the interior (6) of the inner mask (2). In normal operation, air is inhaled and exhaled solely through the inner mask (2) and so substantially no air pressure differential exists between the ambient atmosphere (9) and the cavity (4) which will allow ambient air to enter the cavity.

Abstract: Apparel suitable for providing protection against noxious agents, wherein the apparel comprises a laminate material that provides a substantially effective barrier against the noxious agents. It is preferred that the laminate material comprises two or more layers, at least one of which is a barrier layer that is a substantially effective barrier against the noxious agents and at least one of which is a protective layer that protects the at least one barrier layer.

Abstract: A respirator (1) comprises an inner, oronasal, mask (2) enclosed within an outer, face sealing, mask (3) so as to define a cavity (4) therewith, a screw-threaded air inlet (5) for conducting inhaling air to the interior of the inner mask (2), a filter canister (7) for filtering the inhaling air, and an air outlet (8) for conducting exhaled air from the interior (6) of the inner mask (2). In normal operation, air is inhaled and exhaled solely through the inner mask (2) and so substantially no air pressure differential exists between the ambient atmosphere (9) and the cavity (4) which will allow ambient air to enter the cavity.

Abstract: A respirator system (10; 100) for a worker in an environment with hazardous airborne contaminants comprises a respirator (12, 112), a helmet (14, 114), a camera (40, 140), and a gas sample analyser (16, 116) capable of analysing samples of gas from within the respirator and in the immediate area near the user. An RF emitter (20, 120) sends a signal to a remote receiver (24, 124). The emitted signal is a real time view through the camera (40, 140) and overlaid on that is a graphical representation of the protection factor being achieved by the respirator. The system (100) may also have a data storage device (162, 170) to store data such as how protection factor varies with time and may have a position sensor (160). The provision of the position sensor (160) allows a map of contamination levels with position to be built up as a user moves around a site.